Cationic surfactant based adjuvant systems for some herbicides that increase pH, herbicide solubility and performance

ABSTRACT

A method for increasing the performance of sulfonylurea and sulfonamide herbicides by using blends of cat-ionic surfactants and basic pH adjustors as adjuvants.

CROSS-REFERENCE TO RELATED APPLICATIONS:

1) Nalewaja; John D Aug. 19, 1997 U.S. Pat. No. 5,658,855

2) M. Green et al., “Surfactant Structure and Concentration StronglyAffect Rimsulfuron Activity”, Weed Technology, 1993, vol. 7:633-640.

3) Woznica, Zenon J.; et al. Jul. 3, 2003 Patent Application Number20030125211.

4) Woznica, Zenon J.; et al. Jun. 5, 2003 Patent Application Number20030104947

BACKGROUND OF THE INVENTION

It is known that increasing the pH of the spray solution forsulfonylurea herbicides increases the performance of these herbicides¹.This can be achieved by using a number of pH adjustors which can also beapplied with fertilizers or adjuvant blends. It is thought that theeffect is due to an increase in solubility of these types of herbicidesas the pH increases (WSSA Herbicide Handbook—7th Edition, 1994). Thisinvention pertains to the use of a pH adjustor in a blend of cat-ionicsurfactants. It was discovered that Sulfosulfuron, a sulfonylureaherbicides, performed better when the pH adjustor was combined with acat-ionic surfactant (amine) rather than an oil or a blend of non-Ionicsurfactants as taught by Nalewaja et. al.

SUMMARY OF THE INVENTION

The present invention relates to adjuvant compositions for use in thespray carrier of post emergence herbicides applied as an aqueous spraysolution to crops infested with undesired weeds to control the infestingweeds. Broadly, the adjuvant compositions of the invention comprise anamine or ammonia compounds for adjusting the pH to the alkaline range of9-10.5 and a cat-ionic surface active agent with a highHydrophilic-Lipophilic balance (HLB), which functions as a spreader orsticker and penetrant for use with postemergence sulfonylurea andsulfonamide herbicides when applied in a aqueous spray composition.

Normally the adjuvant is applied as 0.5% v/v (volume to volume) of theaqueous spray solution. In other words the present invention is dilutedwith water (99.5%) to which is added the desired herbicide, normallysulfosulfuron. However, increases in activity have been seen with othersulfonylurea or sulfonamide herbicides.

DETAILED DESCRIPTION OF THE INVENTION

This invention pertains to the unexpected increase in activity seen whensulfosulfuron was applied with a cat-ionic surfactant plus a pH adjustorthat increased the pH to a pH of 9-10.5 (Table 1). As opposed to theincrease in activity that was predicted to happen when applied with anoil based or non-ionic surfactant with a pH adjustor as taught byNalewaja et. al.

This effect has been seen with both wild oat (Avena fatua) Table 1 anddowny brome (Bromus tectorum) Table 2. The increase in activity has beenseen with different formulation of tallow amine cat-ionic surfactant anda pH increasing additive (Table 3).

TABLE 1 The Efficacy (Percent Control) of Sulfosulfuron as Affected byDiffering Spray Adjuvants Applied to Wild Oats. Wild Oat Wild Oat %Control % Control Herbicide Adjuvant 14 DAT 28 DAT Sulfosulfuron Quad 7*48% 62% Sulfosulfuron AQ118** 75% 98% Use Rate of Sulfosulfuron 0.66oz/Acre. Days After Treatment (DAT). *Quad 7: Crop Oil plus nitrogenfertilizer to increase pH and herbicidal activity. **AQ118: Tallow Amine(cat-ionic surfactant) plus Aqua Ammonia.

TABLE 2 The Efficacy (Percent Control) of Sulfosulfuron andPropoxycarbazone-sodium Applied with Differing Spray Adjuvants to DownyBrome (Bromus tectorum). Downy Brome Downy Brome % Control % ControlHerbicide Adjuvant 21 DAT 68 DAT Sulfosulfuron *AQ117 78% 97%Sulfosulfuron **R-11 52% 62% Propoxycarbazone AQ117 73% 90%Propoxycarbazone R-11 52% 67% Ratings made 21 and 68 Days AfterTreatment (DAT *AQ117: Tallow Amine (cat-ionic surfactant) plus AquaAmmonia. **R-11: Non-Ionic surfactant

TABLE 3 The Efficacy (Percent Control) of Sulfosulfuron Applied withDiffering Spray Adjuvants to Downy Brome (Bromus tectorum). Downy BromeDowny Brome % Control % Control Herbicide Adjuvant 17 DAT 87 DATSulfosulfuron *AQ103 30% 92% Sulfosulfuron **AQ104 30% 90% Sulfosulfuron***R-11  5% 77% Ratings made 17 and 68 Days After Treatment (DAT *AQ103:Tallow Amine (cat-ionic surfactant) plus Aqua Ammonia. **AQ104: TallowAmine (cat-ionic surfactant) plus Aqua Ammonia. ***R-11: Non-Ionicsurfactant

The constituents of the proposed mixture are normally made up ofcat-ionic amine surfactant and a pH adjustor that increases the pH. Thecat-ionic surfactant Alkyl Dimethylamines, Alkyl Amidopropylamines,Alkyl Imidazoline, Derivatives Quaternised, Amine Ethoxylates,Quaternary Ammonium Compounds

1. An aqueous herbicidal spray composition comprising an adjuvant blendcomprising a cationic surfactant and a basic pH adjustor in an amounteffective for providing an alkaline pH of above 9 to about 10.5 whenformulated in the aqueous spray composition; and an effective amount ofa sulfonylurea or sulfonamide herbicide.
 2. The composition according toclaim 1 where the alkaline pH adjustor is selected from the groupconsisting of ammonium hydroxide, potassium hydroxide, sodium hydroxidemonoethanolamine, diethanolamine, triethanolamine, and mixtures thereof.3. The composition according to claim 1 where the cationic surfactant isselected from the group consisting of tallow amine, tallow diamine, cocoamines, ether amines, and mixtures thereof.
 4. The composition accordingto claim 1 wherein the adjuvant blend further comprises a nonionicsurfactant selected from the group consisting of linear alcoholethoxylates, secondary alcohol ethoxylates, block copolymers of ethyleneand propylene oxide, and mixtures thereof.
 5. The composition accordingto claim 1 wherein the adjuvant blend further comprises modifiedvegetable oils selected from the group consisting of methylated,ethylated and butylated seed oils and mixtures thereof.
 6. Thecomposition according to claim 1 wherein the adjuvant blend furthercomprises vegetable oils and mixtures thereof.
 7. The compositionaccording to claim 1 wherein the adjuvant blend further comprises blockcopolymers wherein the block copolymers are selected from the groupconsisting of copolymers of propylene oxide and ethylene oxide.
 8. Amethod of controlling weeds which comprises applying a post-emergenceherbicidal spray composition to weeds and/or other undesired vegetation,the herbicidal spray composition comprising; an adjuvant blendcomprising cationic surfactant; a basic pH adjustor in an amounteffective for providing an alkaline pH of above a pH 9 to about 10.5when formulated in a final spray composition: an effective amount of apostemergence herbicide; and additional water to make up the final spraysolution.
 9. A method for controlling weeds according to claim 8 whereinthe postemergence herbicides include but are not limited to sulfonylureaherbicides such as sulfuron, triasulfuron, mesosulfuron-methyl,chlorsulfuron, halosulfuron, metsulfuron, thifensulfuron, tribenuron,bensulfuron, primisulfuron and nicosulfuron.
 10. A method forcontrolling weeds according to claim 8 wherein the postemergenceherbicides include but are not limited to sulfonamide herbicides such aspropoxycarbazone-sodium, propoxycarbazone-sodium and cloransulam-methyl.11. A method for controlling weeds according to claim 8 where thealkaline pH adjustors includes, but are not limited to: ammoniumhydroxide, potassium hydroxide, sodium hydroxide monoethanolamine,diethanolamine, triethanolamine, and a mixtures thereof in sufficientamount to provide a pH of from about 9 to about 10.5 in the finaldiluted aqueous composition.
 12. A method for controlling weedsaccording to claim 8 where the cationic surfactant includes, but are notlimited to: tallow amine, tallow diamine, coco amines, ether amines andmixture thereof.
 13. A method for controlling weeds according to claim 8which contains an alkaline pH adjustor a cationic surfactant andnonionic surfactant is selected from the group consisting of linearalcohol ethoxylates, secondary alcohol ethoxylates, block copolymers ofethylene and propylene oxide, and mixtures thereof.
 14. A method forcontrolling weeds according to claim 8 which contains an alkaline pHadjustor a cationic surfactant and modified vegetable oils selected fromthe group consisting of methylated, ethylated and butylated seed oilsand mixtures thereof.
 15. A method for controlling weeds according toclaim 8 which contains an alkaline pH adjustor a cationic surfactant andvegetable oils and mixtures thereof.
 16. A method for controlling weedsaccording to claim 8 which contains an alkaline pH adjustor a cationicsurfactant and a block copolymers wherein the block copolymers areselected from the group consisting of copolymers of propylene oxide andethylene oxide.
 17. The composition of claim 1 wherein said herbicide isa sulfonylurea.
 18. The composition of claim 1 wherein said herbicide isselected from the group consisting of sulfosulfuron,mesosulfuron-methyl, nicosulfuron, and propoxycarbazone.